Pressure-fluid percussive tool



may 13 1924.

' G. H. GILMAN PRESSURE FLUID PERcUssIvE TOOL Fled June 7, 1915 l. IFHALmi l1.

lllllll Patented May 13, 1924.

UNITE@ STATES PATENT OFFICE.

GEORGE H.' G TLMAN, OF CLAREMONT, NEW I-IAIPSHIRE, ASSIG-NOR TO SULLIVANMACHINERY COMPANY, F BOSTON, MASSACHUSETTS, A CORPORATION OF MASSA-CI-IUSETTS.

'PRESSURE-FLUID PERCUSSIVE TOOL.

Application filed .Tune 7, 1915.

7 '0 @ZZ fw ,71.0 m zt may con cern Be it known that l, GEORGE H.CriLMAN,

a citizen ot the United States. and a resident of Claremont, SullivanCounty, rNew Hampshire, have invented an lm provement in Pressure-FluidPercussive Tools, of which the following description, in conne-ctionwith the accompanying drawings, is a specification, like characters onthe drawings representing like parts.

This invention relates to pressure fluid percussive tools, and is moreparticularly, though not exclusively, concerned with a percussivelyacting drill ot' the hammer type having a hollow drill steel, into whichpres sure luid is discharged to clear the hole ol its cuttings.

My invention will be best understood by reference to the followingspecification. when taken in connection with the accompanying drawingsof one specific embodin ment thereof, while its scope will be moreparticularly pointed ont in the appended claims.

In the drawings:

Fig. 1 is a. plan of a pressure fluid tool embodying my invention, theforward portions of the drill steel being broken away;

Fig. 2 is a sectional view of the same :se on line 2-2 of Fig. 1,showing a portion of the drill steel and a portion of the handle brokenaway; and

Figs. 3 and 4L- are detail sectional views on line 3 of Fig. 1, showingdiii'erent positions of the piston and the piston-controlling valve.

Referring to the drawings, and to the embodiment of my invention which Ihave selected for illustration, 1 have there shown a pressure Huidpercussive tool of the hammer type, having a cylinder 5 provided with apiston chamber 6, in which a piston 7 is arranged to reciprocate. Int-he specific example, the piston is provided with an exten r sionconstituting` a hammer bar 8, which reciprocates in a front cylinderhead 9, and strikes the inner end ot a drill-'bit 10 loosely held in achuck sleeve 11 of a chuck 12, which latter is rotatably mounted in aforward extension 13 ot the cylinder head 9.

Serial No. 32,516.

Rotation may be imparted to the chuck 12 and drill-bit 10, by the piston7, through the use of suitable rotating mechanism of the type formingthe subject matter ot U. S. Letters Patent No. 1,034,010, granted to theSullivan Machinery Company as my assignee July 30th, 1912, or ot U. S.Letters Patent No. 1,103,002, granted to the Sullivan Machinery CompanyJuly 7th, 1914, as assignee of George H. Gilman and Lee A. Knights. Inthe mechanism of each of said patents, the reciprocative movement of thepiston is utilized to impart a st-ep-bystep rotative movement to the:chuck and the drill-bit held thereby in a well-known manner. which itwill be unnecessaryhere to describe, as it forms no essential part of mypresent invention. In the accompanying drawings, 14 is the rotatingmechanism which is similar to that of said patents, and receives itsrotative movement from the piston through the use of one or more helicalgrooves 15 formed in the hammer bar 8, which latter is splined to thechuck 12 by one or more keys 16 working in corresponding keyways 17formed in the hammer bar. A. further illustration and description of therotating mechanism is deemed unnecessary to a proper understanding ofthe subject matter of my present invention.

The drillbit 10 is herein provided with an axial hole 18, to whichgaseous fluid and liquid may be applied for the purpose of expelling thecuttings and laying the dust. As herein shown. the tool is provided witha liquid conducting tube 19, which extends 'trom a rear cylinder head 20axially through the piston 7. This tube, however, forms no part of myinvention herein. and may 'be omitted if desired. It should be noted,however, that as shown, the tube where it extends into the axial passage18 of the drill-bit 10 is separated from the wall of the passage by anannular space, affording a means of communication between the hollowdrill-bit and the chamber 21 within the chuck 12. Into the chamber 21pressure fluid may be admitted from the cylinder chamber 6,'by way ofthe grooves 15 and 17, or either of them, by simply providing thenecessary clearances. One or more of these grooves may enter into thecylinder chamber during the rearward stroke of the piston, and conductmotive fluid from the cylinder chamber 6 to the chuck chamber' 21, fromwhence it will pass to the drill-bit.

The piston 7 may be controlled in its reciprocations by any suitabletype of valve, but for the purposes of illustration, I have herein showna valve similar to that forming the subject matter of Officer Patent 733,229, dated September 8, 1903, and Gilman Patent No. 1,030,466, datedJune 25, 1912. In the specific example herein shown, 22 is a controllingvalve of the pressure Huid pistoncontrolled type, having a central spool23, which alternately connects a supply chamber 24, with ports 25 and26, the former leading to the rear or head end of the cylinder, and thelatter to the forward or tool end of the cylinder. In the position ofthe valve shown in Fig. 2, pressure fluid passes from the supply chamber24 through the port 25 to the rear end of the cylinder, acting to drivethe piston forward, the port 26 at the same time being connected aboutthe contracted or stem portion of the valve, with one end of an exhaustspace 27. IVhen the valve is reversed, the port 26 is connected with thesupply chamber 24, and the port 25 is connected with the opposite end ofthe exhaust space 27.

To reverse the valve, the latter is provided at opposite ends withspools 28 and 29, which work in chambers 30 and 31, to which pressureHuid is alternately admitted by the movement of the piston to throw thevalve. The chamber 30 is connected by a passage 32 to the forwardportion of the cylinder chamber 6, while the chamber 31 is connected bya passage 33 to the rear portion of the cylinder chamber, so that suchpassages are alternately opened by the piston in its reciprocatorymovement to admit pressure iiuid to that end of the valvel chamber withwhich the uncovered passage is connected, and to exhaust the pressurefluid from the opposite end, such. admission of pressure liuid reversingthe position of the valve. Such type of valve is well-known, andrequires no further description, it being herein disclosed and referredto merely as a type of any pressure-fluid actuated valve,

the particular form and construction of such valve being immaterial forthe purposes of the present invention. In the operation of tools of thisclass, it frequentlyv becomes desirable to withdraw the drill-bit fromthe drill hole, meantime supplying pressure fluid continuously to thedrill-bit to cause the discharge of the cuttings from the drill hole,and to stop the percussive action of the hammer piston on the drill-bit.It is desirable, however, that during the withdrawal of the drill-bit,the latter shall be rotated to assist in clearing the hole of itscuttings, and to prevent the drill-bit from sticking as it is withdrawn.To this end, therefore, I have provided means for limiting the movementof the valve to less than normal, to cause the operation of the pistonwith a reduced amplitude of movement, while maintaining communicationbetween the motive fluid supply and the drill steel by way of thecylinder chamber. Such reduced movement of the piston, whileinsufficient to cause it to strike the drill-bit, is still great enoughto operate the rotating mechanism.

These desirable results can be attained very conveniently by the use ofa manuallyoperated push pin or push button 34 arranged at either end ofthe valve, herein at its forward end, so as to limit the motion of thevalve in that direction to less than normal. In the presentexemplification, the movement of the valve is checked by buffers 35 and36, the latter bearing against suitable springs 37 and 38, perforated toreceive tie rods or bolts 39 and 40, having threaded ends engaging nuts41 and 42. The buffer 36 forms a convenient housing for the push buttonor push pin 34, and for that pui pose is herein provided with a chamber43, to receive an enlarged portion 44 of the push pin, whose forwardportion projects through a perforation in the spring 33, and isconveniently accessible to the hand of the operator at a point where itmay be pressed inwardly. The enlarged portion 44 of the push pin limitsits inward motion by engagement with the inner end of the chamber 43,and limits its outward motion by engagement with the spring 33. As ameans for preventing the trapping of air in the chamber 43, which wouldtend to prevent inward motion of the push pin, the enlarged portion 44of the latter is herein provided with a longitudinal groove 46 to ventsaid chamber.

During the normal operation of the tool, the push pin 34 is in itsoutward position, as Shown in Fig. 2, but when it is desired to shortenthe stroke of the piston, itinay be pressed inwardly to the positionshown in Figs. 3 and 4. IVhen this takes place, the valve can still moverearwardly to its full stroke from mid-position, but its forwardmovement from mid-position is so limited (see Fig. 4), that only a verysmall supply of motive fluid passes from the supply chamber 24 throughthe port 25 to the rear end of the cylinder, and hence the forwardstroke of the piston is weakened and shortened, and the reversal of thevalve takes place before the piston reaches the normal forward limit ofits stroke. As a result, the piston is reeiprocated with reducedamplitude in its cylinder, and does not strike the drillbit; butmeantime, pressure Huid is supplied in a lll) practically continuousstream by way of the piston chamber to the drill-bit to clear the holeof its cuttings; while, at the same time, f

ply releasing the push pin, thus permittingl the valve to work its fullstroke.

While I have herein shown and described one specific form or embodimentof my invention for illustrative purposes, and have disclosed anddiscussed in detail the construction and arrangement incidental to onespecific application thereof, it is to be understood that the inventionis limited neither to the mere details or relative arrangement of parts,nor to its specific embodiment herein shown, but that extensivedeviations from the illustrated form or embodiment of the invention maybe made, without departing from the principles thereof.

Having thus described one embodiment of my invention, what I claim anddesire by Letters Patent to secure is l. In a percussive tool, acylinder, a percussive piston therein, means operated by reciprocationof said piston for effecting rotation of a drill steel, fluid supply andeX- haust means including distributing valve means, fluid supply portmeans, and fluid distribution. passages alternately but separatelybrought by said valve means into f communication with said supply portmeans and adapted to conduct pressure fluid to the opposite faces of thepiston, means for controlling movements of said valve means includingpiston controlled means for subjecting said valve means to pressurevariations to eect movements thereof, and means under manual control andmovable between positions respectively wherein it does not adect saidvalve means and wherein it coacts with said valve means to decrease therate of flow of fluid past said valve means to one end of said cylinderwhereby the path of reciprocation of the piston is limited but steelrotation is maintained.

2. ln combination with a hollow drill steel, a percussive toolcomprising a cylinder, a percussive piston in said cylinder, pistoncontrolled steel rotating and cleansing fluid supply means, fluid supplyand eX- haust means for said cylinder including distributing vfalvemeans, fluid supply port means, fluid distribution passages alternatelybut separately brought by said valve means into communication with saidsupply port means and adapted to conduct pressure luid to the oppositefaces of the piston, means for controlling movements of said valve meansincluding piston controlled means for subjecting said valve means topressure variations, and means under manual control and movable betweenpositions respectively wherein it does not affect said valve means andwherein it coacts with said valve means to decrease the rate of flow offluid past said valve means to one end of said cylinder, whereby thepath of reciprocation of the piston is limited but steel rotation andcleansing fluid supply are maintained. y y 3. A percussive toolcomprising, in combination, a cylinder, a piston working therein, adrill bit percussively actuated by said piston, drill bit rotatingmechanism operated by said piston in its reciprocative movements, apiston controlling valve, and manual means to mechanically control thesame and effective to decrease the rate of flow of pressure fluid pastsaid valve to stop the percussive action ofsaid piston, while stillpermitting said fluid to flow at a reduced rate to cause said piston tooperate said rotating mechanism, said manual means being substantiallyinstantaneously operable.

4. In a percussive too-l, in conibination, a drilling motor having acylinder and piston, a hollow drill steel, means for supplying fluidfrom said cylinder to said hollow drill steel a distributing valve forsaid motor, and means under manual control for mechanically governingsaid valve to decrease the rate of flow of pressure fluid past saidvalve while still permitting said fluid to ilow at a reduced rate tosaid tool to operate the same with reduced stroke and at a normal rateto said hollow drill steel.

5. A. percussive tool comprising, in combination, a fluid supplyconnection, a cylinder, a piston reciprocable therein, a hollow drillsteel arranged for percussive actuation by said piston, conduit meansfor supplying pressure fluid from one end of said cylinder to said drillsteel, drill steel rotating mechanism operated by said piston in itsreciprocative movements, a distributing valve alternately connecting theopposite ends of said cylinder with said fluid supply connection, andmeans under manual control for decreasing the rate of flow of pressurefluid past said valve when the latter is connecting the rearward end ofsaid cylinder with the fluid supply connection whereby the percussiveaction of the piston is discontinued, while still permitting fluid toflow to the first named end thereof at undiminished rate when the latteris connected by said valve with the source of fluid supply to cause saidpiston to operate said rotating mechanism and to maintain anuninterrupted fluid flow through said hollow drill steel.

6; In a percussive tool, a hollow drill steel, a reciprocable pressurefluid operated distributing` valve controlling the flow therethrough,and reciprocable coaXially disposed means under manual control forlimiting the movement of said valve while permittingl the same tooperate to maintain an unreduced fluid flow through said drill steel. 7.In a percussive tool, a hollow drill steel, a pressure fluid operateddistributing valve, reciprocable, coaxially disposed means under manualcontrol for lin'iiting the movement of the valve to less than normalwhile permitting thesame to operate, and percussive means controlled bysaid valve and provided with means adapted to form a communicationbetween the motive fluid supply and said drill steel whereby to supp-lycleansing fluid to the latter.

8. In a percussi ve tool, a hollow drill steel, a. reciprocable pressurefluid operated distributing valve, means under manual control andengageable with said valve for limiting the movement ofthe valve to lessthan normal while permitting the same to operate to cause. theopera-tion of the tool with a reduced amplitude of movement, and meanscontrolled by said valve and operative to form a communica-tion betweenthe motive fluid supply and said drill steel whereby the latter' may besupplied with cleansing fluid.

9. In a percussive tool, a work piston, a piston chamber, a pressurefluid operated piston controlling valve adapted when moved in oppositedirections from its midposition to connect opposite sides of said pistonwith a source of fluid pressure, and means under manual controlcomprising a push button movable into the path of said valve forlimiting the movement thereof' in one direction from itsk mid-positionto less 4 than normal while still permitting its normal movement in theopposite direction from mid-position.

10. In a percussive tool, a work piston, a piston chamber, a hollowdrill steel, means adapted to connect said piston chamber and drillsteel, a. pressure fluid operated piston controlling valve, and meansunder manual control and engageable with said valve for limiting themovement of said valve toy less than normal while permitting the same'to operate to cause a reduced amplitude. of movement of said piston.

11. A percussive tool comprising, in combination, a cylinder, a pistonworking'therein, a drill-bit percussively actuated by said piston,drill-bit rotating mechanism operated by said piston in itsreciprocative movements, a piston controlling valve, and meansengageable with said valve to stop the percussive action ofsaid pistononthe drill-bit while still permitting said piston to operate the rotatingmechanism.

12. A percussive tool comprising, in combination, a cylinder, a pistonworking therein, apiston controlling valve, a drill-bit percussivelyactuated by said piston, drill-bit rotating mechanism operated by saidpiston in its reciprocative movements, and means engageable with saidvalve. to limit the movementof said valve to less than normal thereby tocause a reduction of the stroke of said piston while permitting the sameto operate.

13. A percussive tool comprising, in combination, a cylinder, a pistonworking therein, a pressure fluid operated piston controlling valve, adrill-bit rotating mechanis-m operated by said piston in itsreciprocative movements, and manually operable means engageable withsaid valve for limiting the movement of said valve from its mid-positiontoward the end of that movement which causes the forward movement ofsaid piston, while still permitting full movement of said valve in theopposite direction from its midposition.

14. A percussive tool comprising, in combination, a Cylinder, a pistonworking therein, a hollow drill steel percussively actuated by saidpiston, conduit means for supplying pressure fluid from the forward endof said cylinder to said drill steel, a pressure fluid operated pistoncontrolling valve, drill steel rotating` mechanism operated by saidpiston in its reciprocative movements, and manually operable meansengageable with said valve for limiting the movement of said valve fromits mid-position toward the end of that movement which causes the sameto admit fluid to the rear end of said cylinder', while still permittingfull movement of said valve in the opposite direction from itsmidposition, thereby stopping` the percussive action of said piston,While permitting the same to operate said rotating mechanism, andmaintaining a constant fluid flow through said drill steel.

15. In a drillingmechanism, in combination, a hollow drill steel andmeans cooperating therewith comprising a cylinder, a piston reciprocablein said cylinder and adapted to impact said drill steel, drill steelrotating mechanism operated by said piston in its reciprocativemovements, a valve for controlling the supply of pressure fluid toopposite ends of said cylinder, means operative `when said piston is ata predetermined distance from one end of said cylinder to connect thatend with said hollow drill steel, and manually controlled meansengageable at will with said valve to stop the percussive action of saidpiston while rcausing it to effeet operation of said rotatingmeans andperiodically to open said connecting means.

16. In a drilling mechanism, in combination, a hollow drill steel andmeans cooperating therewith comprising a cylinder, a piston reciprocablein said cylinder and adapted to impact said drill steel, drill rotatingmechanism, a valve for controlling the supply of pressure fluid tooffect reciprocation of said piston and rotation of said drill steel,piston controlled means for connecting said drill steel with a source offluid pressure, and manually controlled mea-ns enname to thisspecification, in the presence of gageable with said valve for effectingdistwo subscribing Witnesses continuation of the percussion of saidpiston on said steel While continuing the operation GEORGE H. GILMAN. 5of said rotating means and maintaining said Witnesses: l connectingrmeans in operation. LEE A. KNIGHTS,

In testimony whereof, I have signed my C. H. TIPPING.

